1. Preheat your oven to 350°F (180°C). Line the bottom of a 9-inch (23cm) springform pan with parchment paper.

2. In a medium bowl, combine crushed digestive biscuits, sugar, and softened butter, mixing until well combined. Press this mixture into the prepared pan.

3. Bake the crust for 12-15 minutes, or until it's lightly golden. Allow it to cool completely.

4. Puree blueberries in a blender or food processor until smooth, then strain the mixture through a fine-mesh sieve to remove the seeds.

5. In a large bowl, beat heavy cream until stiff peaks form. In a separate bowl, whisk together egg yolks, vanilla extract, and a pinch of salt.

6. Gradually add sugar to the egg yolks, whisking until pale and fluffy. Melt white chocolate chips in a double boiler or in the microwave in 30-second increments, stirring between each interval until smooth.

7. Fold whipped cream into the egg yolk mixture, then gently fold in the melted white chocolate and blueberry puree.

8. Pour the cheesecake filling over the cooled crust and smooth the top. Bake for 45-50 minutes, or until the edges are set and the center is slightly jiggly.

9. Allow the cheesecake to cool completely in the pan. Once cooled, refrigerate for at least 4 hours or overnight.

10. Just before serving, sprinkle lime zest over the top of the cheesecake. Slice and serve chilled.